In electrical connectors which have removable or mating parts it is difficult to eliminate the necessary assembly clearance to an extent sufficient to prevent moisture migrating into the clearance due to surface tension or capillary effects. Separate flexible seals may be required, and these can increase costs significantly. A reduction of the clearance makes assembly more difficult, and may in any event lead to passage of moisture due to capillary effects.
Among connectors are those, as described for example in JP-A-3-29276, wherein a retainer is used as a means for preventing removal of a terminal fitting housed in a terminal fitting housing chamber. Such a connector has a configuration whereby in its connector housing a retainer insertion hole is formed so as to open out to an outer face thereof, a retainer being attached by being inserted into the retainer insertion hole to retain a terminal fitting.
In the connector described above, since the configuration is such that the retainer insertion hole opens out to the outer face of the connector housing, a small space inevitably occurs between the retainer insertion hole and the retainer. If moisture passes into this space, it tends to be sucked in due to surface tension effects. As a result, this kind of connector is unsuitable in an environment where water is present. Other connectors are used in which a water-proofing means, such as a seal member or the like, is employed, but although such a connector has a high degree of water-proofing, the cost is also substantially increased.
Similar clearances may exist around the periphery of mating connectors, for example in the region of an overlapping hood, and also between mating internal faces of connector housings.
The present invention has been developed after taking these problems into account and aims to prevent movement of moisture in the clearance spaces formed between removable or mating parts of an electrical connector, while maintaining low cost.